Injection nozzle for internal combustion engines



Feb. 18, 1941. MEYER ETAL 2,231,937

INJECTION NOZZLE FOR INTERNAL COMBUSTION ENGINES Filed Nov. 16, 1958 lliilflllfl Jaye/7mm:

Patented Feb. 18, 1941 UNITED STATES:

PATIENT OFFICE 2,231,937 INJECTION NOZZLE FOR-INTERNAL ooM- BUSTION ENGINES.

Application November 16, 1938, Serial No. 240.822

' v .In Germany December 14, 1937 4 Claims.

The, present invention relates to cooled injection nozzles for internal'combustion engines, of the type having a nozzle body in which the end from which the fuel passes into the cylinder of the engine is so enclosed by a cooling jacket, that between the cooling jacket and the nozzle body there is formed a hollow space for the reception of a cooling liquid.

The purpose of the invention is to achieve cf- 10 fective cooling by simple means and, despite limited space conditions, to bring comparatively large amounts of cooling medium into the vicinity of the points to be cooled. According to the present invention an injec-' tion nozzle for internal combustion engines is provided with a substantially cylindrical jacket surrounding its fuel outlet end, through which jacket a cooling fluid is circulated, said jacket be ing firmly connected with the said nozzle around 20 the fuel outlet point and sealed at its opposite end by a suitable nut to the outside of the body of said nozzle.

The invention is more particularly described with reference to the accompanying drawing, in

25 which:

Figure 1 is a longitudinal section through a nozzle on the line 1-1 in Figure 2.

Figure 2 is a cross section on the line II in Figure 1,

60 Figure 3 is a longitudinal section on the line III-III in Figure 2.

Figure 4 is a cross section on the line IVIV in Figure 1, and

Figure 5 is a longitudinal section through a 35 modified form of construction of a nozzle.

In the drawing:

Numeral l is a nozzle holder, to the end surface 2 of which a nozzle body 3 is attached. In the interior of the nozzle body 3 is disposed a 40 nozzle needle 4, which is pressed on to a seating surface 5 by a spring. The fuel passes through a conduit 6 provided in the nozzle holder into a conduit 1 in the nozzle body 3. From here, the fuel flows through annular spaces 8, 9 towards the 45 seating surface 5 of the nozzle and, as soon as the pressure from the injection pump (not shown) has become large enough to overcome the force of the said spring, it raises the nozzle needle 4, so that fuel is injected at Ill into the cylinder of the to engine or into a primary chamber or the like.

Surrounding the orifice ill, the nozzle body 3 is firmly connected by braz ng with one end of acooling jacket II. The other end l2 of the cooling jacket ll is constructed as a flange which is bindingly pressed against a shoulder M on the nozzle body 3 by a cap nut l3. In order to obtain eflicient tightness without bending of the parts despite the heating during the soldering process, it is desirable to effect the brazing in a tightly clamped condition.- Welding may be'em- 6 ployed for connecting the parts with each other, if desired, instead of brazing. 7

The nozzle body 3 is reducedin diameter where it is surrounded by the cooling jacket I I; such that its cross section has substantially the shape shown 10 in Figure 4. By means of this reduction, a hollow space l5 has been provided for the reception of a cooling liquid. In the example of construction shown, the hollow space I5 is of a horse shoe section intersected by a bar [6, which, according to Figures 3 and 4, consists of one piece with the nozzle body 3 and bears tightly on the inner wall of the cooling jacket ll. As shown inFigure 3, a conduit H is provided in the bar I6 which is connected between the hollow space-l5 through a .part of the jacket in the direction of the arrow 20 in the immediate vicinity of the part to be cooled. As shown in Figure 3, a conduit 2| leads from above the hollow space l5 and leads through a conduit 22 in the nozzle holder to the cooling oil return pipe (not shown). As may be seen in Figure 2 and as indicated in "Figure 4, by the sign'X, the conduit 2| begins on that side of the bar' l6 which is' opposite to the conduit l8. The cooling medium is consequently forced to traverse the entire hollow space l5 from the lower end of the one side of the bar lB-to the upper end of the other side of the bar l6 and to cool the en- 40.

tire lower part of the nozzle eflectively. With this arrangement, despite the small space that is available especially in vehicle engines for installing the lower nozzle parts, a comparatively large cooling medium chamber can be utilised advantageously for the cooling. Further, the cooling jacket can be manufactured cheaply as a simple part, preferably as a pressed piece. For locking the nozzle body 3 relative to the nozzle holder l, as shown in Figures 1 and 2, a holding pin 23 is employed. 1 Another form of construction of the invention is shown in Figure 5. This (fillers from the form of construction according to Figures 1 to 4 only in that with this construction the cooling jacket Ila is tightened by means of the conical construction of the outer jacket by an appropriate inner cone 7 24 in the cap nut I3a instead of the flange as radially in one direction from the nozzle body it" self and bears with its outer surface on the inner used in the construction according to Figures 1 to 4.

We' declare that what we claim is:

l. A fuel injection nozzle for internal combustion engines, including a nozzle body and a cooling'jacket surrounding its fuel outlet end, in which a. bar or rib extends .axially of, and projects wall of the cooling jacket, so as to form a seal therewith providing a single longitudinal partition end of the nozzle body.

2. A fuel injection nozzle as claimed in claim 1, having a conduit for the return of the cooling fluid,

which conduit commences at that end of the,

hollow space'remote from the outlet end of the nozzle body.

3. A fuel injection nozzle as claimed in claim 1. having a conduit for the return of cooling fluid from the hollow space, and in which the bar or rib is formed in one piece with the nozzle body, and the outlet end of the passage for the supply of cooling fluid to the space is located on one side surface of 'the rib, while the inlet to the return conduit from the hollow space is located at the opposite side of the bar or rib and remote from the outlet end of the supply passage.

4. A fuel injection nozzle as claimed in claim 1, in which a movable needle valve is pressed under spring pressure onto a seating surface formed in the nozzle body, and in which the outlet opening for the cooling fluid supply is provided in the bar in the region of the plane of the seating surface and is directed substantially tangentially of the curvature of the nozzle body periphery.

ALFRED MEYER.

WALTER IJPPART. 

